Only the latest release receives security fixes.

Please use GitHub's private vulnerability reporting for this repository (Security → Report a vulnerability) rather than opening a public issue.

Castline is local-first: your data lives in plain JSON files on your machine, and the app only makes outbound requests to webhook URLs / API endpoints you configure yourself. Reports about the inbound HTTP endpoint (token handling, 127.0.0.1 binding) and the connector send paths are particularly appreciated.

Your data folder (Settings → Data & backups → Open folder) stores secrets in plaintext, which is standard for a local-first desktop app:

• settings.json holds your OpenRouter API key and the inbound-endpoint bearer token.
• CLAUDE.md (generated for the AI agent) embeds the endpoint token while the endpoint is on.

Treat backups and exports of this folder as sensitive — don't commit it to a repo, put it in a shared drive, or paste its contents anywhere. If a secret is exposed, rotate it: regenerate the endpoint token in the Connectors tab, and revoke/replace the OpenRouter key at openrouter.ai/keys.

The endpoint is off by default, binds 127.0.0.1 only, uses a random 256-bit token, rejects browser cross-site requests, and rate-limits repeated bad tokens. Exposing it to the internet via a tunnel is possible but at your own risk — see the README. For internet-facing automation, prefer the forthcoming hosted Castline Cloud API over tunnelling a loopback server.